Patients receive oral calcitriol once daily on days 1-3 alone on week 1. Beginning on week 3, patients receive calcitriol as in week 1 and oral dexamethasone on days 0-4. Courses repeat every 2 weeks in the absence of disease progression or unacceptable toxicity.

PROJECTED ACCRUAL: A total of 56 patients (28 per stratum) will be accrued for this study.

Eligibility

Ages Eligible for Study:

18 Years and older

Genders Eligible for Study:

Male

Accepts Healthy Volunteers:

No

Criteria

DISEASE CHARACTERISTICS:

Histologically confirmed adenocarcinoma of the prostate meeting all of the following criteria:

At least 3 prostate-specific antigen (PSA) measurements obtained over at least 90 days after radical prostatectomy on post-radiotherapy PSA nadir must be available

PSA at least 2 ng/mL after prostatectomy OR at least 4 ng/mL after prior radiotherapy

Patients previously treated with radiotherapy must have a PSA clearly rising from lowest value within 6 months after completion of therapy

PATIENT CHARACTERISTICS:

Age

18 and over

Performance status

ECOG 0-1

Life expectancy

At least 12 months

Hematopoietic

Platelet count at least 100,000/mm^3

Hemoglobin at least 10 g/dL

Hepatic

Bilirubin no greater than upper limit of normal (ULN)

Alkaline phosphatase no greater than 2 times ULN

Renal

Creatinine less than 1.8 mg/dL

Phosphorus normal

No hypercalcemia (albumin-corrected calcium greater than ULN)

No nephrolithiasis

Single episode of renal lithiasis allowed provided episode occurred more than 5 years prior to study

Other

Fertile patients must use effective double-barrier contraception for at least 1 week before, during, and for at least 2 weeks after study

No symptomatic pancreatitis

No uncontrolled diabetes

No known or suspected inability to comply with study requirements (e.g., abuse of alcohol/drugs or psychotic states)

Curatively treated condition associated with renal stones (e.g., hyperparathyroidism, bladder dysfunction, or obstructive uropathy) allowed provided patient has been free of stone formation for more than 5 years

No prior hormonal therapy for prostate cancer more than 3 months after definitive local therapy

No concurrent androgen therapy

Radiotherapy

See Disease Characteristics

More than 3 months since prior radiotherapy for locally recurrent prostate cancer

No concurrent radiotherapy, including for pain control

Surgery

See Disease Characteristics

Other

More than 4 weeks since prior investigational drugs

No concurrent medication known to affect systemic calcium metabolism, including any of the following:

More than 400 IU of cholecalciferol supplements

More than 500 IU of vitamin A supplements

Calcium supplements

Fluoride

Antiepileptics

Contacts and Locations

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study.
To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below.
For general information, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: NCT00054522